Package filling and sealing system



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3311- 13, 1970- L. .1. CSERNAK PACKAGE FILLING AND SEALING SYSTEM 13 Sheets-Sheet 15 Filed May 28, 1965 United States Patent M 3,488,914 PACKAGE FILLING AND SEALING SYSTEM Laszlo J. Csernak, Philadelphia, Pa., assignor to FMC Corporation, San Jose, Calif., a corporation of Delaware Filed May 28, 1965, Ser. No. 459,768

Int. Cl. B65b 31/02, 9/12, 51/30 US. Cl. 53-112 25 Claims ABSTRACT OF THE DISCLOSURE The package filling and sealing system disclosed herein makes use of a pouch forming and filling machine of the type that utilized a plastic or paper web and forms it into a tube. The tube is transversely cut and sealed at longitudinally spaced intervals by vise-like cutting and sealing dies which are reciprocated longitudinally relative to the tube. The dies also serve to incrementally feed the web material. In making the upper transverse seal of each pouch a non-sealed portion is provided.

Upon severing of the pouch from the web it is received by a vacuum chamber having opposed flat plates that are actuated to flatten and smooth the pouch while the atmosphere is exhausted therefrom. When the pouch is evacuated sealing jaws in the vacuum chamber complete the upper seal and then the package is removed from the chamber.

This invention relates to the packaging of various products and particularly those that are sensitive to oxygen contamination and has for an object the provision of a package filling and sealing system embodying an improved method of an apparatus for producing sealed packages from which the air has been removed.

The invention is particularly related to systems for making sealed packages from flexible webbing, such as Pliofilm, Mylar, laminates cellophane and the like from which gas or vapor, generically termed air, is withdrawn prior to final sealing of the package. Evacuated packages of this general type have heretofore been produced by various methods and apparatus an example of which is described and illustrated in Sonneborn et a1. Patent No. 2,387,812. However, such prior system has left something to be desired, particularly in the way of speed and degree of evacuation, because in such system the air was withdrawn from the packages while they were surrounded by air at atmospheric pressure and before their detachment from the webbing. In accordance with the present invention, the package is evacuated and sealed after detachment from the webbing so as not to delay the filling of succeeding packages to be formed from the webbing. Although various prior art systems have utilized evacuated chambers for performing the final sealing of packages, such systems have, in general, required extra handling of the packages.

In accordance with the present invention, there is utilized a vertical tube packaging machine with a vacuum turret positioned under the tube thereby enabling direct transfer of partially sealed and filled packages into the turret without diverting or extra handling of the packages. The process of making the package from beginning to end is a one direction vertical motion produced by the packaging machine and by gravity within the turret.

3,488,914 Patented Jan. 13, 1970 More specifically, and in accordance with the present invention, there is provided a method of and means for sealing the opposed longitudinal edges of web material to form a web tube about a vertical axis. A transverse sealis produced at the bottom end of the tube of web material and a predetermined quantity of product inserted into the vertical web tube. The vertical web tube is partially sealed transversely thereof above the top'level of the product to produce a partially sealed package. The partially sealed package is severed from the web tube! thereby causing it to drop by gravity along the vertical axis where it is caught and rotated away from the vertical axis and in a plane substantially perpendicular thereto while evacuating the package. Thereafter, the package is completely sealed and returns substantially to its former position along the vertical axis where it is released for removal from the system.

Sealed packages which have been produced by evacuation only will result in a hard package when subjected to atmospheric pressure as the product therein will become tightly packed due to the evacuation of the air from the interior of the package. The present system is also suitable for the formation of what is known in the trade as a soft package. With this process, after the package has been evacuated and before the seal is made, an inert gas is introduced into the package and the package thereafter sealed. The softness of the package can be controlled by the amount of gas introduced into the package. A slight negative pressure inside the package results in a flat, soft pack with no ballooning eifect.

Further in accordance with the invention, there is provided apparatus for evacuating and sealing packages comprising a turret rotatable about a vertical axis including a plurality of radially disposed pocket means each adapted to receive a package to be sealed. Each of the pocket means includes top door means and bottom door means. The apparatus further includes means for evacuating each of the pocket means when both of its door means are closed thereby evacuating the package in the pocket means. Sealing means is disposed within each of the pocket means for sealing the package and the apparatus further includes means for cyclically controlling the opening and closing of the top door means and the bottom door means of each of the pocket means to remove a sealed package and to receive another package for evacuation and sealing.

In accordance with a further aspect of the invention, the apparatus includes means to raise and lower the turret and means to vary the spacing between the top door means and the bottom door means of each of the pocket means to accommodate packages of different lengths. The pocket means each includes a tubular section between the top door means and the bottom door means interchangeable with other similar tubular sections of different lengths corresponding to the length of the packages to be sealed in the pocket means.

In accordance with another aspect of the invention, there is provided a method of and means for forming web material into a tube, transversely sealing the bottom end of the tube of web material, inserting a predetermined quantity of product into the web tube, and withdrawing air from above the level of the product in the tube of web material prior to producing a transverse seal in the web tube above the level of the product.

Further in accordance with the invention, there is proided a method of and means for sealing and exhausting .ll' from a filled package of web material open at the op end thereof by flattening opposite sides of the filled Iackage while exhausting air therefrom, and sealing the ackage above the level of filling in the package.

In accordance with another aspect of the invention, here is provided a sealed package of flexible web material nd method of making the same. The sealed package comrises a tube of web material having a pair of spaced ransverse seals at opposite ends of the tube formingthe op and bottom end seals of the package, and the bottom nd seal has its ends at the edges of the package curved lpwardly toward the top end seal in avoidance of leaks at he bottom corners of the sealed package.

Further in accordance with the invention, there is pro- 'ided a filled sealed package comprising a tube of thermolastic web material having a transverse seal extending LCI'OSS the bottom end of the tube forming the bottom eal of the package. A filling is disposed within the tube ll'ld a second transverse seal extends across the tube above he level of the filling therein and forms the top end seal )f the package. The bottom end seal has its outer ends :urved upwardly toward the top end seal to eliminate :harp corners at the bottom end of the package in avoidtnce of corner leaks in the sealed package. The package is :vacuated and at least one pair of opposite sides of the illed package are substantially fiat and parallel. This pro- IidCS a sealed package which is particularly suited for multiple packing in shipping containers.

For a more detailed description of the invention and for further objects and advantages thereof, reference is :o be had to the following description taken in conjunc- ;ion with the accompanying drawings in which:

FIG. 1 is a perspective view of a package filling and iealing system embodying the present invention;

FIG. 2 is a schematic view of the drawbar and transverse sealing mechanism of the filling machine of FIG. 1;

FIGS. 3 and 3A are exploded views of the transverse sealing mechanism, the cutoff mechanism and the package stripper mechanism shown in FIG. 2;

FIG. 4 is a vertical sectional view showing a vacuum deflator assembly associated with the seam seal tube and filling tube of the mandrel for deflating the package after a charge of product has been introduced therein;

FIG. 4A is a vertical sectional view along the lines 4A--4A in FIG. 4C;

FIG. 4B is a vertical sectional view along the lines 4B4B in FIG. 4C;

FIG. 4C is a horizontal sectional view along the lines 4C4C of FIG. 4;

FIG. 4D is a fractional exploded perspective view of the piston chambers for the actuator member of the vacuum deflator in FIG. 4;

FIG. 4B is a fractional exploded perspective view of the vacuum ports in FIG. 4B;

FIG. 5 is a top plan view of the vacuum turret shown in FIG. 1;

FIG. 6 is a vertical sectional view of one of the banks of switches shown in FIG. 5;

FIG. 6A is an enlarged fractional view partly in section of the lower end of the stationary center post which carries the plurality of cams as illustrated in FIG. 6;

FIG. 7 is a vertical sectional view of the drive mechanism for the vacuum turret taken along the lines 7-7 in FIG. 5;

FIG. 8 is a vertical sectional view of one of the turret pockets taken along the lines 88 in FIG. 5;

FIG. 8A is a fractional view showing the top door of the turret pocket in FIG. 8 in its open position;

FIG. 8B is a fractional sectional view taken along the lines 8B8B in FIG. 8 showing details of the spring biased shoe and its relationship to the bottom door of the turret pocket;

FIG. 8C is a fractional view of the sealing dies in FIG. 8;

FIG. 9 is a schematic diagram of the piping system with associated electrically operated valves for the pockets of the turret;

FIG. 10 is a schematic electrical diagram of the system;

FIG. 11 is a timing diagram graphically illustrating the various operations of the vacuum packaging system;

FIG. 12 is a schematic diagram showing one of the pockets of the turret in section and including mechanical flatteners for flattening the sides of the package to be evacuated and sealed in the pocket of the turret;

FIG. 13 is a fractional sectional view showing details of one of the mechanical package flatteners of FIG. 12; and

FIGS. 14-14C are views of the package during different steps of its formation.

Referring to FIG. 1, there is illustrated a package filling and sealing system embodying the present invention. A Web W of Pliofilm, Mylar, cellophane or like sheet material. preferably of the type which seals to itself upon application of heat and pressure, is fed from a supply roll R thereof about a web-shaping member 11 of any suitable shape, carried by a packaging machine 10 generally of the type disclosed in US. Patents 2,200,971 and 2,387,812 but with various improvements as hereinafter pointed out. The web-shaping member 11 is adapted to bring the margins of the web W into overlapping relation to form a web tube T extending beyond the lower end of the form or mandrel 12 which includes a hollow filling tube. The web W is fed intermittently by means of a reciprocating feeding structure F, as hereinafter described, to form successive sections of the web tube T, and between the successive feeding movements a heated vertical sealing device 13 is moved toward the mandrel 12 to press together and seal the overlapping margins of the web tube T and, thus, form a vertical seal S extending longitudinally of the web tube T.

The feeding structure F is adapted to reciprocate on the spaced vertical rods 15 with the length of the feeding stroke being controlled in accordance with the length of package to be produced. The feeding structure F has been illustrated at the bottom of its stroke. As the Web feeding structure F arrives at the top position of its stroke, near the lower end of the mandrel 12, a pair of spaced elongated members 16 and 17, FIG. 2, th reof move toward one another from opposite sides of the web tube T to flatten is beyond the lower end of the mandrel 12. The members 16 and 17 respectively carry sealing tools 18 and 19, FIG. 2, which transversely seal the web tube T. The heat sealing tools 18 and 19 are of improved construction and include means from forming the complete transverse bottom seal S of a container or package and means for producing a partial transverse seal S in the web tube T at the top of a container or package, FIG. 14.

When the system is first placed in operation at the start of a run, the web feeding structure F is at its upper position and the web tube T is flattened to produce the bottom transverse seal S for the first package to be filled. A predetermined amount of product is discharged into the web tube T from a suitable filling machine 22 having a hopper 23, of an auger feeding device of known construction, connected at the upper end of the filling tube 12. The measured product passes through the filling tube 12 into the package to be formed and which, at this time, has been sealed on its bottom. The measured charge of product arrives in the package before the web feeding structure F reaches the bottom of its stroke as shown in full line in FIG. 1. When the Web feeding structure F reaches the top of its stroke, as previously described, the jaws or sealing tools 18 and 19, along with a pair of web grippers 24, 24, FIG. 2, close to flatten the web t me T transversely and produce a partial seal S FIG. 14, in the top of the package that has just been filled and a continuous transverse seal S on the bottom of the next package to be filled. On the descent or downward stroke of the web feeding structure F, the package just produced is severed from the web tube T.

As may be seen in FIG. 2, a knife is carried by and movable with respect to the elongated member 16 and sealing tool 18 to cut the webbing between a package clamped by sealing tools 18 and 19 and the package next to be filled and sealed. The sealing tool 19, carried by the other elongated member 17, is provided with a recess 26 extending across the face of the sealing tool 19 between the raised portions thereof which produce the transverse top and bottom seals S and S The recess or slot 26 is adapted to receive the knife 25 which pierces the webbing while the latter is maintained under tension. The knife 25 transversely severs the Webbing before the elongated members 16 and 17 release it at or near the end of a feeding stroke of the web feeding structure F.

Positioned beneath the vertical filling tube 12 of the packaging machine 10 is a rotatable vacuum turret 30 comprising a plurality of equally spaced radial pockets 31 which are adapted to receive the partially sealed packages from the packaging machine 10, rotates the partially sealed packages away from the vertical axis of the filling tube 12 and in a plane substantially vertical thereto while evacuating the packages, thereafter completing the seal of the packages and returning the packages in succession in sealed condiiton to substantially their former position along the vertical axis for release of the sealed packages by the vacuum turret 30. As hereinafter described, the sealed packages are adapted to drop by gravity from the bottom of the pockets 31 at approximately the time that the rotatable turret 30 completes a 360 revolution of the pocket containing the package. Thus, it will be seen that each sealed package is released approximately on the vertical axis of the filling tube 12 and the sealed package will drop from the bottom end of the vacuum turret 30 onto a discharge chute D and slides onto a belt B of an endless conveyor C which discharges the sealed packages P from the package filling and sealing system.

Referring to FIGS. 1 and 2., the drive for the feeding structure F is provided by a electric motor M which is connected to a suitable speed reducer or variable drive transmission 32 of known construction having an output shaft 33 which carries a fly Wheel 34 and has a beveled gear 35 at its opposite end which mates with a beveled gear 36 on a one-time vertical shaft 37 in the packaging machine 10. The fly wheel 34 has a T-shaped slot 34a extending across the diameter thereof which is adapted to have adjustably secured therein a cam roller 39 which is adapted to extend into a cam slot 40a in a link 40. One end of link 40 is secured at pivot 40b to the frame of the packaging machine 10 while the opposite end of link 40 is secured at pivot 40c to a second link 41, the opposite end of which is connected by an adjustable pin 42 to the lower part of the drawbar 43 of the feeding structure F. Adjustment of the cam roller 39 lengthwise of slot 34a between the center of the fly wheel 34 and the end of the slot 34a thereof will control the length of stroke of the drawbar 43 of the feeding structure F. Adjustment of the pin 42 within the slot 43a enables the drawbar 43 to be adjusted so that it may start each stroke of the feeding structure F at the same vertical position regardless of the total length of the feeding stroke of the feeding structure F which, as pointed out above, corresponds to the length of package to be produced. The one-time shaft 37 is provided at its upper end with a sprocket 45 around which passes a sprocket chain 46 which also passes around a sprocket 47 on a cam shaft 48 in the packaging machine 10. The sprockets 45 and 47 have a one-to-one ratio, thus the onetime shaft 37 is utilized to control all of the operations,

of the packaging machine 10 such as the filling operation, the formation of the vertical seal in the web tube, the formation of the packages, the stripping of the packages from the sealing tools, the operation of the cutoff knife and the operation of the web snubber which moves against the web near the upper end of the filling tube and prevents the web from sliding down during high speed operation of the machine which may cause the web to be moved down further than required. The lower end of the one-time shaft 37 is also provided with a sprocket 50 around which passes a chain 51 which also passes around a sprocket 52 carried by the lower end of the splined turret drive shaft 53 of the turret 30 as later to be described.

Referring to FIGS. 2, 3 and 3A, it will be seen that the elongated members 16 and 17 are slidably supported for horizontal movement on four parallel rods 55, the opposite ends of which are supported by the drawer 43 of the feeding structure F. As may be seen in FIG. 2, the members 16 and 17, respectively, support sealing tools 18 and 19, each of which respectively supports a top gripper 24 and a bottom gripper or stripper 56. The top grippers 24 are of spring loaded construction and are adapted to engage the web tube prior to the heated faces of the heat sealing tools 18 and 19 so that pulling of the web during the downward stroke of the feeding structure F will be accomplished by the gripping members 24 rather than by the heat sealing tools 18 and 19 alone. This construction is particularly desirable where the Web material has a tendency to stretch during the application of heat.

As may be seen in FIG. 2, each of the elongated members 16 and 17 is adapted to be actuated by a toggle linkage comprising a link 58 pivotally connected at pivot 59 to one arm of a bell crank 60, the other arm of which is pivotally connected to one end of a piston rod 61 which is adapted to be actuated pneumatically by an air cylinder 62. The bell cranks are pivotally supported by a pin 60a which, in turn, is carried by a bracket 63 which, in turn, is carried by a diaphragm 64 supported by the drawbar 43 of the feeding structure F. The diaphragm 64 extends over a chamber 65 which is adapted to be supplied with air pressure by way of a passage 66.

In constructing sealing dies for packaging machines, it is important that you be able to control the alignment of the sealing dies and you should also be able to control the amount of pressure applied to the sealing dies. The control of pressure is important as this will vary depending upon the type of web material to be sealed. If too high a pressure is applied to the web material, the seal may be damaged during formation or if too low a pressure is applied, the seal may not be completed during formation. The present invention provides for both of these requirements, the alignment feature being discussed further in connection with FIGS. 3 and 3A.

Referring to FIG. 2, it will be seen that the pressure cylinders 62 are adapted to operate their respective toggle linkages 5860 which, in turn, are adapted to reciprocate the elongated members 16 and 17. Air is adapted to be applied to the pressure cylinder 62 from a suitable supply by way of a solenoid operated valve which is adapted to be energized from a switch 71 operated by a cam 72 mounted on the cam shaft 48 of the packaging machine 10. The cam 72 is shaped to operate the valve 70 for movement between a retracted position of the air cylinders 62 to an over center position of the toggle linkages 5860 as controlled by an adjustable stop 6% which is adapted to engage the links 58 to maintain the pivot 59 slightly below a horizontal position with respect to the adjacent arms 58 and 60. The adjustable stops 60b permit the air cylinders 62 to bring the sealing dies 18 and 19 approximately into engagement with each other, however, they do not provide the final sealing pressure to the sealing dies 18 and 19. The final sealing pressure is applied by means of the diaphragms 64 which, in turn,

.re connected to the end of the straightened toggle linkvges 58-60 by way of bracket 63 and thereby apply the ealing pressure to the heated die tools 18 and 19. The liaphragms 64 have a substantial area, say for example, n the order of fifty square inches, and, thus, for a relaively small amount of movement, may apply a substanial force to the heat sealing dies 18 and 19. From the oregoing, it will be seen that the pressure cylinders 62 )rovide for most of the reciprocating movement of the teat sealing dies 18 and 19 while the sealing pressure is tpplied by the diaphragms 64. The pressure diaphragms 54 are supplied with air by way of a suitable solenoid )perated valve 74 which is adapted to be energized from L switch 75 operated by a cam 76 mounted on the cam haft 48.

After the heat sealing dies or tools 18 and 19 have :ompleted the foregoing sealing operation, the filled and )artially sealed package is ready to be severed from the 'emainder of the web tube. As pointed out earlier, the artialy sealed package is severed from the web tube durng the descent or downward stroke of the feeding strucure F. The knife 25 is actuated by a pair of pistons 25a, 16. 3, mounted within corresponding cylinders 16a in :longated member 16. The pistons 25a and, thus, the :nife 25 are adapted to be actuated by a solenoid operated air valve 78, FIG. 2, which is energized by a switch 79 adapted to be operated from a cam 80 mounted on the :am shaft 48 of the packaging machine 10.

As pointed out above, the elongated members 16 and [7 each are adapted to support a pair of strippers 56 which are carried on the ends of piston rods of air cyliniers 56a. The air cylinders 56a move the grippers 56 .oward each other to grip the webbing therebetween while :he heat sealing tools 18 and 19 are completing :heir sealing operation. When the heat sealing .ools 18 and 19 are withdrawn or moved to )pen position by collapsing the toggle linkages con- :rolled by air cylinders 62, the air cylinders 56a con- :inue to apply air pressure to their pistons, thus, main- :aining the strippers 56 in engagement with the webbing even though the cylinders 56a are being moved apart along with the elongated members 16 and 17. Thus, the severed and partially sealed package will be momentarily gripped by the strippers 56 and the heat sealing tools 18 and 19 will be pulled out of engagement with the sealed areas of the partially sealed package thereby stripping the package from the faces of the heat sealing tools 18 and 19. This operation only requires a fraction of a second and the grippers 56 move apart permitting the partially sealed package to drop into one of the pockets 31 of the vacuum turet 30, FIG. 1. The cylinders 56a for the strippers 56 are adapted to be controlled by means of a solenoid operated valve 82, FIG. 2, which is energized by a switch 83 operated by a cam 84 mounted on the cam shaft 48 of the packaging machine 10.

Referring to FIGS. 3 and 3A, it will be seen that each of the heat sealing tools 18 and 19 is provided with electrical heaters H of any suitable type and preferably including a thermostatic device T controlling the temperature. The heat sealing tool 18 is provided with a rib 18a which extends across the full face of the die for producing the bottom seal S FIG. 14. Associated with the rib 18a is a pair of die blocks 18b which include curved portions for forming curved seal areas S at the ends of the bottom seal S of the packages. The die blocks 18b, FIG. 3, are adapted to be disposed in the slot 180 in the sealing tool 18. The die blocks 18b are spaced apart a distance corresponding to the width of the package to be formed and are maintained in position by means of set screws 18d which extend through the top of the sealing tool 18. The top gripper device 24 is adapted to be positioned between the two upper projections of the heat sealing tool 18 and secured in place by a pair of screws 189 which extend into holes 18 in the heat sealing tool 18. The gripper device 24 includes a pair of compression springs 24a which normally position the front edge of the gripper 24 so that it projects beyond the edge of the heat sealing rib 18a. Thus, the gripper 24 will engage a side of the web tube before the rib 18a engages the web.

The cutting knife 25 is adapted to extend through a slot 18g in the heat sealing tool 18. The cutting knife 25 is provided with notches 25b which are adapted to receive the forward ends of the pistons 25a, the rear ends of the pistons 25a being adapted to reciprocate within cylinders 16a formed within the elongated member 16.

The top partial seal S for the package is formed by a plurality of die blocks 18h which are spaced along a bottom slot 18k in the heat sealing tool 18. The die blocks 18h are adapted to be secured within the slot 18k by means of set screws 18m. In practice, one of the die blocks 18h will be positioned in slot 18k half way between the ends of the tool 18. The die blocks on either side of the center die block 18h are so positioned that they will form a partial seal at the end portions of the package. For the majority of sizes of packages, there will be a center seal and two end seals, thus, leaving two air passages into the package through the top seal for evacuation of the package. The two end die members 18h shown in FIG. 3 are adapted to center the heat sealing tool 18 with regard to the mating heat sealing tool 19 shown in FIG. 3A. The purpose of the partial seal S at the top of the packages, FIG. 14, is to maintain the front and back layers of the web of the package flat so that the final seal S FIG. 14B, will not wrinkle when it is completed in the pockets of the turret 30. The rounded corners 8 FIGS. 14-14B, are produced adjacent the bottom seal S of the package to prevent leakage at the bottom corners resulting from abrasion and handling of the package including the dropping of the finished package P from the turret 30 as well as vibration of the completed packages P during shipment. When the package is completed and drops out of the turret onto the conveyor belt B, this would have an effect on the corner seal and tend to produce a leaker unless the corner seal was adequately constructed. As may be seen in FIG. 14B, the distance from the bottom corner of the package P to the inner edge of the seal S is a substantial distance and, thus, any leakage through the bottom corners of the package is minimized or substantially eliminated.

Referring to FIG. 3A, there is there illustrated in exploded form, the various parts carried by the elongated member 17 of the feeding structure F. the heat sealing die 19 is provided with a continuous longitudinal rib 19a which cooperates with the corresponding rib 18a in FIG. 3 in producing the bottom seal S on the package P, FIG. 143. The heat for the heat sealing tool 19 is provided by heating elements H controlled by thermostat T The rounded corners S at the opposite ends of the bottom seal S FIGS. 14-14C, are adapted to be produced by the rounded or curved corner blocks 19b, FIG. 3A, which are adapted to be received in slots of mounting blocks 19g. The screws 19d extend through the blocks 19g and secure the die blocks 19b in place therein. The upper Web gripper device 24 which is biased outwardly by means of compression springs 24a is mounted on the heat sealing tool 19 by means of screws 192 which extend into holes 19 Thus, it will be seen that the gripper device 24 of FIG. 3A is adapted to cooperate with the corresponding gripper device 24 shown in FIG. 3 and associated with the heat sealing tool 18.

Referring again to FIG. 3A, it will be seen that there is a slot 26 which extends lengthwise of the heat sealing tool 19 and is adapted to receive the knife blade 25 of FIG. 3. The blade 25 is pushed through the web into the slot 26 and by a piercing action on the web severs a partially sealed package from the web tube. The partial seal S at the top of a package is produced by a plurality of die blocks 1% which are disposed in a slot 19k of the heat sealing device 19 and are adjustably secured in place by set screws 19m. The die mounting blocks 19g are adapted to be resiliently mounted on the heat sealing tool 19 by means of the compression springs 1911 and the screws 190 which extend through the back of the heat sealing device 19 and into the mounting blocks 19g. Thus, it will be seen that the curved corner sealing blocks 19b are resiliently mounted on the heat sealing device 19 and are adapted to cooperate with the corner sealing dies 18b of the heat sealing device 18 in FIG. 3. Likewise, the sealing dies 19h for producing the partial top seal S on the packages are mounted for cooperation with the corresponding top seal dies 18h of FIG. 3.

As pointed out above, it is important that the alignment of the dies be controlled. In FIG. 3A it will be seen that alignment of the heat sealing device 19 with respect to the horizontal or X-axis is provided by a V- groove 19p which extends transversely of the heat sealing device 19 and is adapted to receive a dowel pin 17b which is adapted to be held in place by means of a mounting block 17c having a corresponding V-groove 17d. The mounting block 170 is adapted to be secured to the rear of the heat sealing tool 19 by means of a plurality of screws 17a and Belleville spring Washers 17 The back of the mounting block 170 is provided with a vertical V-groove 17g which is adapted to receive a dowel 17h. The dowel 17h is held in position by means of a second mounting block 17k having a vertical V-groove 17m therein which is adapted to engage the dowel 17h. The block 17k is secured to the mounting block 170 by a plurality of screws 1711 and Belleville spring washers 17p. The mounting block 17k is adapted to be received within a recess 17a in the elongated member 17 and the block 17k is secured to member 17 by means of screws 17q. Thus, it will be seen that the vertical dowel 17h permits adjustment of the heat sealing device 19 about the vertical or Y-axis and the horizontal dowel 17b permits adjustment of the heat sealing device 19 about the X-axis or horizontal. The various spring washers and compression spring provide for a resilient mounting of the heat sealing tool 19 and aid in insuring that the heat sealing tools 18 and 19 will mate perfectly during sealing operations.

As pointed out above, the seat sealing devices or tools 18 and 19 carry upper gripper members 24 which are adapted to relieve the tension on the web tube when it is being fed. They also include lower gripper members 56 which are carried on pistons 56b which, in turn, are carried in cylinders 56a, the latter being carried by the heat sealing tools 18 and 19 and movable therewith. The bottom grippers 56 are used as stripping means to strip the packages from the faces of the heat sealing dies after the top partial seal has been made. This insures that the packages will enter the pockets 31 of the turret at the proper time. Although the cylinders 56a are withdrawn with the heat sealing tools 18 and 19, the pistons 56b remain extended to keep the strippers 56 in engagement with the partially sealed package, thus stripping the partially sealed package from the die faces. The bottom grippers 56 also support package guide plates .57, FIGS. 2, 3 and 3A, which are adapted to engage opposite sides of the filled packages. The guide plates 57 partially shape the packages so that their thickness is less than that of the openings in the pockets 31. The plates 57 also prevent swaying of the packages and guide them into the pockets 31.

The packaging machine 10, FIG. 1, is operable over a wide range of speeds depending upon the size of packages being produced. For smaller packages, the speed of operation will be higher than for larger packages. In general, the range of speeds is from about thirty to sixty packages per minute. One limiting factor on the speed of operation of the packaging machine is the time required for the transverse bottom seal S to cool. This will vary depending upon the type of web material utilized. Since the product from the filling machine is placed in the web tube immediately after the formation of the bottom seal of the package, it is necessary that the bottom seal be sufiiciently strong to avoid being opened under the load of the product.

It is an object of the present invention to provide a vacuum defiator device for the web tube so as to partially evacuate the package while it is still attached to the web tube on the filling machine but after the measured quantity of product has been placed in the web tube and before the partial top seal has been made. The purpose of the partial evacuation is to suck the air out of the package to a degree suflicient that the side walls of the package will be pressed together above the product level by the atmospheric pressure outside of the package. It should be noted that the evacuation within the web tube is only sufiicient to bring the webs within about a quarter of an inch of each other and they dont completely touch each other. It is only after the partial top seal has been made at the top of the package and the package cut olf from the web tube that the atmospheric pressure forces the top portions of the package against each other. Such an arrangement is shown in FIG. 4 where the opposing web portions have been illustrated as being drawn close to each other by means of the vacuum defiator device 90, hereinafter to be described.

The vacuum defiator device comprises a pair of ring members 91 and 92 which are adapted to be bolted one on top of each other to form an assembly which is inserted in the lower end of the seam seal tube or mandrel 12 and around the inner auger filling tube 12a, FIG. 4. The vacuum defiator device 90 is secured in place by three spaced clamp screws 93, FIG. 4A, which extend upwardly into the bottom ring 92 and are adapted to engage radially extending pins 94 which are forced outwardly of the ring 92 and into engagement with the inner circumference of the seam seal tube 12 by means of the cam surfaces 93a at the opposite ends of the clamping screws 93. The bottom ring member 92 of assembly 90 supports a stainless steel diaphragm or gate 95 which is secured to a pivoted backup plate 96, FIG. 4. The backup plate 96 is pivotally sup ported from the ring member 92 by means of a pivot pin 99. As may be seen in FIG. 4, the backup plate 96 is provided with a shoulder 96a adjacent the pivot pin 99. The shoulder 96a is adapted to be engaged by the lower end of a pusher rod 100 which extends vertically through the ring 92. The upper end of the pusher rod 100 is secured to a semicircular ring 101 of flexible construction which is secured by a pair of screws 102 to the upper ring 91.

The upper ring 91 is provided with a piston chamber which, as shown in FIG. 4D, includes six cylinders interconnected with each other by grooves 105a and which cylinders 105 are adapted to receive six pistons 106, the lower ends of which are adapted to engage the semicircular flexible ring member 101, FIG. 4C. The chamber 104 in ring 91 is of segmental shape and communicates with the cylinders 105 of FIG. 4D. The chamber 104 is provided with a segmental member 104a having a passage there through which is adapted to be connected to an air line 103 for introducing air pressure into the chamber 104. The air line 103 extends upwardly between the seam seal tube 12 and the auger tube 12a and is connected to a three-way air control valve, not shown. The air control valve is of the solenoid actuated type and is operated by means of a switch 110, FIG. 2, which, in turn, is operated by a cam 111 carried by the cam shaft 48 in the packaging machine 10. The single hose 103, connected to the passage in member 104a, supplies air to the chamber 104 and the six small pistons 106. When the valve is actuated, the air pressure applied to the pistons 106 causes the pistons 106 to move downwardly against the semicircular pivotal ring member 101 thereby moving the pusher 100 downwardly against the shoulder 96a on the backup plate 96. This causes the diaphragm plate 95 to be moved to closed or sealing position with respect to the knife edge 92:: which extends around the inner periphery of the ring 92. This seals the lower end of the auger filling tube 12a with respect to the interior of the web tube but the stainless steel diaphragm 95 does not engage the end of the auger tube 12a as shown in FIG. 4.

As may be seen in FIGS. 43, 4C and 4B, the vacuum defiator assembly 90 is provided with a plurality of vacuum holes or passages 113 which extend through the lower ring 92 and up into the upper ring 91 where they communicate with a common chamber 114 which, in turn, is connected through member 114a to a suction hose 115. The chamber 114 and member 114a are similar to the chamber 104 and member 104a for the air pistons. The vacuum to the chamber 114 is controlled by means of a three-way solenoid operated valve, not shown, which is adapted to be energized by means of a switch 117 which, in turn, is operated by means of a cam 118 on the cam shaft 48, the latter being shown in FIG. 2.

The vacuum defiator device 90 is adapted to be operated after a measured charge has been deposited into the web tube. At that time, the cam 111, FIG. 2, operates switch 110 thereby operating its associated solenoid valve to supply air to chamber 104 in ring 91, FIG. 4, causing the pusher 100 to move downwardly and pivot the backup plate 96 into its upper position with the diaphragm plate 95 in sealing position against the knife edge 92a of ring 92. With the auger tube 12a thus sealed off with respect to the interior of the web tube T, the cam 118, FIG. 2, is effective to actuate the associated switch 117 and its associated vacuum solenoid valve to apply suction by way of hose 115 to the vacuum chamber 114 and associated holes 113 communicating with the lower ring 92 of the vacuum defiator device 90-. This causes the air in the web tube T to be withdrawn and causes the web to move from its dotted line position in FIG. 4 to its full line position where the opposite sides of the web tube are approximately one-quarter inch apart.

The bottom ring 92 is also provided with a peripheral sealing diaphragm 120 extending around ring 92 and over the peripheral groove 120a therein. The peripheral sealing diaphragm 120, secured at its edges to ring 92, is of the inflatable type and has an air connection, through passage 103a, with the air supply 103 for actuating the pusher 100. The inflatable seal diaphragm 120 is adapted to be inflated when air is applied to the pusher 100 to operate the plate 95. The sealing diaphragm 120 will be inflated to extend around the lower end of the seam seal tube 12 and bear against the web forming a seal with it, as shown in FIG. 4, thus preventing leakage between the web and the seam seal tube 12. If the web is sufficiently flexible so that it is drawn against the seam seal tube by the suction applied through the vacuum holes 113 to the interior of the web tube, then the inflatable seal 120 need not be used.

In operation, the entrapped air in the package is compressed by the guide plates 57 causing a strain on the bottom seal S The vacuum defiator '90 minimizes this condition. Thus, it will be seen that the purpose of the vacuum defiator 90 is not to evacuate the package but is to insure a reliable bottom seal by relieving the pressure from the seal while it is still hot. This is accomplished by removing the air from the package to a substantial degree adequate to bring the two web faces close to each other as shown in FIG. 4. This enables the packaging machine to operate at higher speeds since it does not place as much pressure on the bottom seal S while it is still hot. Thus, it enables the bottom seal to cool with less load on it and thereby form a better seal.

Vacuum turret The operation of the vacuum turret 30 will now be described. Referring to FIG. 5, the vacuum turret 30 has been illustrated as including six radial pockets 31 disposed at 60 intervals about the central axis of the turret. Each of the pockets 31 is of identical construction with the other and each is provided with a bank s of switches. Each bank s of switches includes six switches s -s as shown in FIG. 6. Each of the switches s -s is provided with a cam follower which is adapted to engage the corresponding cams c c mounted on the cam shaft 150. The cam shaft is normally stationary while the banks s of switches s -s are adapted to rotate about the cam shaft 150. The cam shaft 150 is supported in a bearing 151 which is mounted in a rotatable bearing support 152 which also serves as the rotatable support for the banks s of switches. The lower end of the cam shaft 150 is provided with a cross pin 154 which is biased outwardly of the shaft 150 by means of a compression spring 155, FIG. 6A. The cross pin 154 is adapted to engage a stationary pipe in the vacuum turret 30 as later to be described and, thus, maintain the cam shaft 150 stationary. However, in setting up the vacuum turret and testing it preparatory to a run, it is frequently desirable to operate the various mechanisms in the respective pockets 31 which are controlled by the cams c -c on the cam shaft 150.

In order to operate these mechanisms without requiring rotation of the vacuum turret 30, the upper end of the cam shaft 150 is provided with a knob 156 so that the cams c -c may be rotated relative to the banks s of switches. The cross pin 154 is adapted to be received in a slot at the upper end of the stationary pipe 160, FIG. 7. When the knob 156 is rotated, the pipe 160 will causethe cross pin 154 to move up in the slot in the lower end of cam shaft 150, FIGS. 6A and 7, thereby compressing the spring 155 and permitting the cams c c to rotate relative to the banks s of switches but in opposite direction to the normal rotation of the turret 30.

It will be recalled from the description of FIG. 2 that the lower end of the one-time shaft 37 of the packaging machine 10 is provided with a sprocket 50 around which passes the chain 51 which also passes around the sprocket 52 at the lower end of the splined turret drive shaft 53. This connection is also shown in FIG. 7. The shaft 53 is splined for height adjustment, as later to be described. The shaft 53 includes a flexible coupling 162 for ease in assembly of the vacuum turret and the upper end of the shaft 53 is provided with a sprocket 163 around which passes a chain 164 which meshes with a sprocket 165 on the main turret column 166.

The vacuum turret 30 makes one-sixth of a revolution for each revolution of the one-time shaft 37 of the packaging machine 10. The reason for this is that the vacuum turret 30 has six pockets 31 and, thus, receives six packages from the packaging machine 10 during each revolution of the turret 30. To accomplish this, in the particular embodiment illustrated, the sprocket 50 has a oneto-three ratio with respect to sprocket 52 on the turret drive shaft 53 and the sprocket 1 63 on turret drive shaft 53 has a ratio of one-to-two with respect to the sprocket 165 on the main turret column 166. The upper end of the main turret column 166 is supported in a pair of spaced bearings 167, 168 which are supported by a stationary main bearing housing 169 carried by a top plate 170 which, in turn, is supported on three telescoping legs or posts 171 disposed equidistantly around the central axis of the main turret column 166.

As may be seen in FIG. 7, the upper end of the main turret column 166 is provided with a collar or annular ring 173 which has bolted thereto, as by bolts 174, a rotatable plate 175 which is adapted to support the pockets 31 of the turret for rotation. The lower portion of the main turret column 166 is supported in a pair of bearings 177 and 178 which, in turn, are supported by a stationary bearing housing 179 in the form of a casting which also houses the rotary seals 181 and 182.

The stationary pipe 160 passes through the center of the main turret column 166 and the lower end thereof is threaded at 160a for engagement with a threaded flange 184. The lower end of the pipe 160' is provided with a connection 16% for receiving an air supply. The air is adapted to pass upwardly through the interior of pipe 160 into a manifold A supported on the rotatable plate 175 of the turret. A gas of air connection 186 is provided in the casting 179 near the lower end thereof. This connection 186 is adapted to communicate with the interior of the housing 179 beneath the seal 182 and with the interior of pipe 187 through which pipe 160 extends. The lower end of the pipe 187 is surrounded by a spring loaded self aligning static seal 188 which is part of seal 182 and the upper end of the pipe 187 is provided with a threaded collar 189 which secures the pipe 187 to a manifold G and forms a seal with it through an O-ring. Thus, it will be seen that the pipe 187 is adapted to rotate with the manifold G for gas. The pipe 160 is stationary and the upper end thereof is supported in a bearing 190 which is, in turn, supported in a bearing housing 191 secured to and rotatable with the manifold A for air. The bearing housing 191 also supports a plurality of se'aling rings 192 which surround the upper end of stationary shaft 160 and seal the manifold A and the manifold G with respect to each other.

There is a third manifold at the top of the main turret column, the third manifold being for vacuum and identified by the reference character V. The vacuum connection 194 is carried by the stationary casting 179 at the lower end of the main turret column 166 which provides the vacuum path to the vacuum manifold V. The pipe 187 is maintained centrally of the main turret column 166 by three radial ribs 195. The seals 181 and 182 are effective to keep the gas or air from entering the vacuum line in the turret.

The telescoping legs or posts 171 each comprise a telescope shaft 171a having a shaft stud 17111 secured to the upper end thereof and which extends through the stationary plate 170 and is secured thereto by a nut 1710. A nut member 171d is pinned to the lower end of the telescope shaft 171a and is adapted to matewith the threads on the shaft or lead screw 171e, the lower end of which is supported for rotation in a thrust bearing 171 and a bushing 171g, the latter being supported by the turret base plate 200. The turret base plate 200- is supported by a. plurality of spacers 201, the lower ends of which engage the upper surface of a floor plate 202. A telescope sleeve 171h surrounds the telescope shaft 171a, th upper end of the sleeve 171k being provided with bushings 171k and the lower end of the sleeve 171k being supported on the turret base plate 200 by a bracket 200a.

The lower end of each of the lead screws 171:; of the thre telescoping legs 171 is provided with a sprocket 203 around which passes a common sprocket chain 204. One of the telescope legs 171 is provided with a second sprocket 205 on the lower end of the lead screw 171e around which passes a sprocket chain 206 which also passes around a sprocket 207 secured to a sprocket stud 208, the lower end of which is supported by the floor plate 202. The upper end of the sprocket stud 208 is accessible through an opening in the sprocket cover 209, FIG. 1, and is adapted for rotation by means of a hand crank. Thus, it will be seen that rotation of the sprocket stud 208 will, in turn, rotate the lead screw 171e of each of the turret legs 171 by way of the common sprocket chain 204 thereby causing the telescope shafts 171a to be raised or lowered as the case may be. The telescope shafts 171a, in turn, raise the top plate 170 which supports the bearing housing 169 and the main turret column 166 and the parts carried thereby including the rotatable turret plate 175 which supports the pockets 31 of the turret 30.

It will be noted in FIG. 7 that the turret drive shaft 53 also is constructed for telescopic movement. The drive shaft 53 is provided with an inner splined shaft 53a which is connected by the flexible coupling 162 to the upper section of shaft 53 which is supported in a bearing 211 carried by a bearing block 212 which is suspended from the lower surface of the top plate 170. A collar 213 is connected to the upper end of shaft 53 and engages the upper surface of bearing 211. The lower section of shaft 53 is supported for rotation in a pair of spaced pillow blocks 214 which are carried by a pillow block base 215 supported on the turret base plate 200. Thus, it will be seen as the teelscope legs 171 raise or lower the top plate 17 0, the splined shaft 53a will likewise be raised or lowered to adjust the overall length of the turret drive shaft 53 accordingly. The purpose of changing the height of the turret 30 is to compensate for changes in the length of the packages to be produced.

In FIG. 7 it will be seen that there are two stationary brush holder assemblies 220 and 221 which respectively carry brushes 222, 223 and 224, 225, schematically shown in FIG. 10. The brushes 222225, respectively, engage slip rings 226-229 and provide the electrical connections for the electrical circuit of the turret 30 as later to be described in connection with FIG. 10. While the brush holder assemblies 220, 221 are held stationary, the slip rings 226-229, FIG. 10, are supported for rotation on the main turret column 166. In order to hold the housing 179 stationary so that it does not rotate with the rotating parts of the turret, there is provided a vertical adjusting plate 231 having a U-slot in the lower end thereof which receives a pin 232 which extends horizontally from the seal housing 179.

The top plate 170, FIG. 7, also supports in depending relation, a pair of shafts 235 which, in turn, are adapted to support a bnacket 236 for a pulley 237 of the conveyor C, FIG. 1. The conveyor belt B is adapted to pass around the conveyor pulley 237 and the conveyor bracket 236 is adapted for manual adjustment lengthwise of the shafts 235 to change the vertical position of the conveyor relative to the bottom of the pockets 31 of the turret 30.

As mentioned above, each of the pockets 31 of the turret 30 are the same and one of the pockets 31 has been shown in vertical cross section in FIG. 8. The pockets 31 comprise an assembly of parts as now to be described. As may be seen in FIG. 8, there is a jaw housing 250, the opposite sides of which support opposed pairs of air cylinders 251. One pair of the air cylinders 251 support a male heat sealing die or jaw 252 and the other pair of air cylinders 251 support a female heat sealing die or jaw 253. The heat sealing jaws 252 and 253 are adapted to be reciprocated by their respective air cylinders 251 t bring the heat sealing faces 252a and 253a thereof into engagement with the sides of the web package at the upper end thereof and complete the top seal for the package. This is best seen in FIG. 8C and it will be noted that the male die portion 252a has a slightly smaller radius than the female die portion 253a. Thus, when the heat sealing dies 252 and 253 are closed, a maximum force is established in the die faces 252a and 253a at the horizontal center line thereof due to line contact. The spacing between the die portions 252a and 253a increases to either side of the horizontal center line thereby insuring a perfect seal of the webbing material at some location between the die portions 252a and 253a. It will be understood that the heat sealing die portions 252a and 253a are of sufiicient length to extend across the full width of the package to be sealed as the top seal to be formed in the package at this time is a complete seal rather than a partial seal as previously described in connection with the packaging machine 10. The height of the pocket 31 is predetermined with relation to the length of the package to be sealed so that the final top seal S FIG. 14B, produced by the heat sealing jaws 252 and 253 is approximately one-eighth inch below the partial seal S previously produced in the packaging machine 10. The purpose of this is to insure that the final seal at the top of the package is produced at a location in the web material which has not been previously subjected to the horizontal heat sealing dies so that the heat sealing material in the web will be effective in producing the final seal.

The jaw housing 250 supports in depending relation a pair of adjustable tie rod devices 255, FIG. 8, which support, at their lower ends, an adjusting flange 256. A vacuum chamber 257 of tubular construction with adapter 

